1. Field of the Invention
The invention relates to a method for activating at least one temporarily inactive network component of a network system for a vehicle, especially for a motor vehicle. The invention also relates to a corresponding network system.
2. Related Art
Known network systems for vehicles, particularly motor vehicles, are based in most cases on serial bus systems. An example of such a bus system for networking various control devices for implementing system-wide functions of a vehicle is an asynchronous, serial bus system based on the CAN bus (Controller Area Network). Another example is a LIN: Local Interconnect Network Bus System. Since the electrical power is supplied in many vehicles by an energy store of limited storage capacity, it is desirable that non-active parts of the network do not absorb any power or absorb as little power as possible.
In the bus systems used in the field of application for vehicles, an energy detection concept is used. The entire bus system is initially inactive; it is only an energy pulse on the bus line of the bus system that leads to the controller “waking up” and activating the entire system in response. In this context, the energy pulse can be, for example, a data frame or a single voltage pulse. In such a system, the demand for quiescent current is extremely low but all components connected to the bus system are activated and “wake up” in response to the pulse or signal.
For stationary networks, the “Wake on LAN” standard (WOL) has been established for some time (LAN: Local Area Network). It enables inactive hosts in the network to be selectively awakened by a so-called magic packet, an Ethernet frame that contains the MAC address of the host to be awakened and recognized by the corresponding host Ethernet controller.
However, this technology is unsuitable for use in the automotive or motor vehicle field since the network controllers themselves must be active or at least partially active to recognize such a packet. As a result, the demand for quiescent current is far too great for an automotive environment.